The present invention relates to a circuit for transmitting signals across a magnetic boundary.
Semiconductor power devices of various types are used in electronic and electrical devices to operate them. For example, power MOSFETs or IGBTs are used to supply power to such electronic or electrical devices. These power MOSFETs and IGBTs, in turn, are controlled by gate drivers that are coupled to the gates of the power MOSFETs and IGBTs.
The potential difference between the input side and the output side is generally 3-20 volts. However, the required voltage isolation capacity tends to be very large in certain applications, e.g., 3750 volts or more, to protect against sudden spikes or fault conditions. Accordingly, the input side and the output side are isolated from each other using various different techniques. One method is to use a transformer as an interface between the input and output sides. Such a transformer requires one or more magnetic components and windings.
In the past, the transformer tended to be bulky and was placed external to a packaged gate driver. Recently, a packaged gate driver including a magnetic component has been disclosed. One such a gate driver is disclosed in U.S. patent application Ser. No. 11/329,934, filed on Jan. 10, 2006, which is incorporated by reference. One or more magnetic components are included within the package to provide a smaller footprint and more designing flexibility to engineers. However, the magnetic components included within the package would need to be significantly smaller than those used for the conventional transformers.